Will a new plan on one line affect the other lines?

Just Moved In



All 4 lines on my account are under the "YourChoicve Premium 50" plan with 14gigs of data shared between them.
I'm upgrading one of the phones but the only available plans are the Simple Share and Peace of Mind.

The gentlemen outside the Telus store advised us that selecting the "Simple Share 10Gig" should not affect the other lines in any way.


Is this the right information? Just want to make sure I won't muck up the other lines at all